Tub/Shower has cold, hot and diverter knobs installed 1969 during home build. There has been a drip for some time from the faucet and turning the diverter knob causes the drip to transfer to the shower head as expected. Recently the drip has gotten worse so I figured i would give it some attention.

I came to the conclusion that if i installed a 100% shutoff valve behind the shower head I could stop the leak and simply keep the diverter turned to the shower head. This stopped the drip from the shower head and the diverter is keeping all water directed to the shower head, no drip at the faucet. So I thought I was good to go wiped up all signs of water and checked on it a bit later.

To my surprise I see a stream of water running down the shower wall where the flange sets against the shower wall. Water obviously coming from the face of the valve through the screw on extension tube and out the flange. Both hot and cold are leaking like this. Had another thought and turned both hot and cold full on and all leakage stops.

Now here is a question why when I have the bath water valves open keeping constant pressure at the shower head shutoff valve are the other faucets in the home slow to warm and water not hot as it was when tub water was off. I assume that by allowing the water to stay on but not flowing in the shower all I have done is changed the location of the shutoff from the hot /cold knobs to the self installed shut off valve.

This is not the correct fix for this.
How did you put a shut off on the shower riser? solder?...
If you install shutoffs behind tub wall you might as well replace the shower body

The diverter stem has a bad washer and or the seat behind the diverter is also bad.

The fix:
Make shore your knobs are completely closed pending on the stem you might get away with channel locks to take out the stem. Check to washers and the seat inside the body one if not both are bad
You might need to have a seat pulled with a seat puller or try flat head to get in the groves tap it in with hammer the with channel locks counter clockwise to screw out the set
Bring the parts to local hardware store if it's that old of a system
They might have it or tell you were you can get one.

Do these steps reversed to put it back together. Leave the shut off on

This is not the correct fix for this.
How did you put a shut off on the shower riser? solder?...
If you install shutoffs behind tub wall you might as well replace the shower body

The fix:
Make shore your knobs are completely closed pending on the stem you might get away with channel locks to take out the stem. Check to washers and the seat inside the body one if not both are bad
You might need to have a seat pulled with a seat puller or try flat head to get in the groves tap it in with hammer the with channel locks counter clockwise to screw out the set
Bring the parts to local hardware store if it's that old of a system
They might have it or tell you were you can get one.

Do these steps reversed to put it back together. Leave the shut off on

I removed threaded shower head and installed threaded inline shutoff valve and then the shower head to the valve. This was not meant to be a permanant solution to the leak but a method to stop wasting water till fixed properly

The diverter as i said is funtioning properly it ports water where it is set to do so

I have the tools on order to remove the recessed vales in side the shower wall to check seal situation

Fix the faucet to stop the leak. Cartridges, or, washers & seats whatever it takes. Don't strip out the seats using an improper tool!

Flatheads, hammers, & Channel Locks are not the proper tools and may turn a small inexpensive job into a large expensive job!

Please read How To Replace Faucet Washers before doing anything. The article shows the proper tools and discusses the proper methods to replace washers and seat in a faucet.

Placing the valve on the shower arm and having both hot and cold valves open allows the hot and cold water to crossover and affects the temperature on the other fixtures.

If the seat is cracked then it needs to come out if you go to the local shop or HD you will have to buy a pack of the seat fitters all different sizes this can add up $$$
I have about 5-10 different size seat pullers half the time they don't fit that's when my wide flathead comes in 100% I get them out.
Channel locks are a plumbers best friend.
Oh yeah if the stem is resest into the wall then there you will have to buy a pack of them the metal sleeve covers.

The proper seat wrenches have served me well, and when one strips which is seldom a seat extractor works well.

I've never resorted to a flathead and a hammer...

Lol you should try it some day it's fun! when there is no more of that stupid square inside that seat for your seat tool to grip in there yup jam that flat head in there The ends of the flat head groove it's self in the then take your locks and screw it out

Lol you should try it some day it's fun! when there is no more of that stupid square inside that seat for your seat tool to grip in there yup jam that flat head in there The ends of the flat head groove it's self in the then take your locks and screw it out

Thanks for the tip...

I've got the process pictured perfectly well in my mind should whatever methods I use ever fail me.